We sell step thru frames to men all the time. Whatever it takes to create a fun comfortable safe riding experience.
Specialized Roll in step thru size large fits me fine at 5'11" Trek has one of my favorites the step thru Verve as well as a step thru 7.3fx Disc that is quite nice. Its either 19" or 20" I can't recall.
We have used Dropper Seatposts with remote handlebar switches from the mountain bike realm to help some people with hip mobility problems. Drop the seat all the way down as you come to a stop. Feet stable and Saddle is out of the way as you swing off.